Olivia Mode Configuration
This guide covers Olivia-specific settings in fldigi. Make sure you've completed the basic setup first.
Olivia Mode Reference
Olivia uses a Bandwidth/Tones format (e.g., 500/16 = 500 Hz bandwidth, 16 tones). More tones = better weak signal performance but slower speed.
| Format | Center (Hz) | Baud | WPM | S/N (dB) | Use Case |
|---|---|---|---|---|---|
| 500/16 | 750 | 31.25 | ~20 | -13 | Most popular, good balance |
| 500/8 | 750 | 62.5 | ~30 | -11 | Faster, moderate signals |
| 250/8 | 625 | 31.25 | ~15 | -14 | Crowded bands, weak signals |
| 1000/32 | 1000 | 31.25 | ~24 | -12 | Wide, excellent weak signal |
| 1000/16 | 1000 | 62.5 | ~39 | -10 | Fast, strong signals |
| 500/4 | 750 | 125 | ~40 | -10 | Fastest 500Hz mode |
| 125/4 | 625 | 31.25 | ~10 | -15 | Best weak signal, very slow |
Choosing a Mode
Start with 500/16 - it's the most common and offers a good balance. Switch to faster modes (500/8, 500/4) when signals are strong, or narrower modes (250/8) when the band is crowded.
fldigi Olivia Settings
Open Configure → Modems → Olivia
Tune Margin (Search)
Determines how far from center frequency Olivia will search for a signal to decode.
- Default: 8 - Good for most situations
- Lower (4 or 2): When adjacent signals are overlapping
- Higher (16-32): When you can't see the signal clearly on waterfall
Integration Period (Sync)
How "deep" Olivia searches in the noise. Higher = better weak signal decode but longer delay.
| Mode Type | Recommended Setting | Expected Delay |
|---|---|---|
| Standard (500/16, 1000/32, 250/8) | 4 | ~15-20 seconds |
| Standard + weak signals | 5-10 | ~20-30 seconds |
| Fast (500/4, 500/8, 1000/16) | 6-10 | ~15-20 seconds |
Warning: Setting this too high (50-100) for standard modes can result in minutes of delay before decoding starts!
Squelch
Turn it OFF!
Olivia decodes signals well below the noise floor. If you squelch at the noise level, you'll miss these weak signals. Yes, you'll see "garbage" characters when no signal is present - that's normal and harmless.
Soundcard Calibration
Olivia (and other MFSK modes) is more sensitive to soundcard timing errors than PSK or RTTY. Calibration can significantly improve decode quality.
Why Calibrate?
Most soundcards are slightly off in their sampling rate. You won't notice this playing music, but it can cause:
- Strong signals that decode poorly or erratically
- Characters that appear garbled despite good signal strength
- Transmissions that drift or sound "off" to receiving stations
How to Calibrate
- Method 1: Use CheckSR.exe (included with MixW trial version)
- Enter your soundcard sample rate (usually 44100 or 48000 Hz)
- Run for 15-30 minutes until PPM values stabilize
- Note the RX ppm and TX ppm values
- Method 2: Use fldigi's built-in calibration (WWV method)
- Tune to WWV (5, 10, or 15 MHz)
- Use the calibration wizard in Configure → Sound Card → Settings
Entering Calibration Values in fldigi
- Go to Configure → Sound Card → Settings tab
- Enter your values in RX ppm and TX ppm fields
- Click Save
Typical values are small numbers like 50-200 ppm (positive or negative).
RSID (Reed-Solomon ID)
RSID automatically transmits your mode at the start of each transmission, helping other stations identify and auto-switch to your mode.
Enable RSID
- Go to Configure → IDs
- Check Transmit RSID
- Optionally check Receive RSID to auto-detect incoming modes
Benefit: Other operators' software can automatically switch to your Olivia format when they click on your signal!
Test Your Setup
Pre-Flight Checklist
- ✅ Radio in DATA mode (not SSB/CW)
- ✅ fldigi showing correct frequency from rig control
- ✅ Audio levels set correctly (waterfall shows signals, not clipping)
- ✅ Olivia mode selected (Op Mode → MFSK → Olivia-500-16)
- ✅ Squelch OFF
- ✅ Integration Period set to 4 (for 500/16)
- ✅ Tune Margin set to 8
- ✅ PTT working (test with TX button at low power)
First QSO Tips
- Start on 40m (7035-7038 kHz) or 20m (14072-14075 kHz)
- Use Auto CQ macro, wait 45-60 seconds between calls
- Be patient - decoding takes time!
- If you hear a signal but can't decode, try increasing Integration Period